.sao-lei {
    margin: 0px auto;
    margin-top: 100px;
}
.cover-img {
    width: 100%;
    height: auto;
    display: block;
    font-size: 0;
    vertical-align: top;
}
.text-success {
    color: #f00;
    font-size: 20px;
    line-height: 20px;
    white-space: nowrap;
    text-align: center;
}
.btn {
    width:100px;
    height: 30px;
    line-height: 28px;
    text-align: center;
    border-radius: 5px;
    color: #fff;
    font-weight: bold;
    display: block;
    margin: 0 auto;
    text-shadow: none;
    border: none;
    cursor: pointer;
}
.btn:hover {
    background: #0094ff;
}
.btn-primary {
    background: #003cff;
}